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                    箭头函数
            
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                    原型继承
            
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                    模块化Module
            
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                    异常处理
            
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                    编程风格
            
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                    js 扩展
            
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                    浏览器对象
            
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                    操作DOM
            
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                    AJAX
            
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                    Canvas
            
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                    选择器
            
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                    层级选择器
            
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                    事件
            
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                    动画
            
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                    AJAX
            
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                    扩展
            
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                    Nodejs
            
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                    模块
            
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                    path
            
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                    zlib压缩解压缩
            
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                    net网络
            
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                    http
            
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                    express框架
            
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                    process 进程
            
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                    child_process
            
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                    React
            
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<span class="hljs-keyword">var</span> divs = <span class="hljs-built_in">document</span>.getElementsByTagName(<span class="hljs-string">&apos;div&apos;</span>);

<span class="hljs-comment">// &#x67E5;&#x627E;&lt;p class=&quot;red&quot;&gt;&#xFF1A;</span>
<span class="hljs-keyword">var</span> ps = <span class="hljs-built_in">document</span>.getElementsByTagName(<span class="hljs-string">&apos;p&apos;</span>);
<span class="hljs-comment">// &#x8FC7;&#x6EE4;&#x51FA;class=&quot;red&quot;:</span>
<span class="hljs-comment">// <span class="hljs-doctag">TODO:</span></span>

<span class="hljs-comment">// &#x67E5;&#x627E;&lt;table class=&quot;green&quot;&gt;&#x91CC;&#x9762;&#x7684;&#x6240;&#x6709;&lt;tr&gt;&#xFF1A;</span>
<span class="hljs-keyword">var</span> table = ...
for (<span class="hljs-keyword">var</span> i=<span class="hljs-number">0</span>; i&lt;table.children; i++) {
    <span class="hljs-comment">// <span class="hljs-doctag">TODO:</span> &#x8FC7;&#x6EE4;&#x51FA;&lt;tr&gt;</span>
}
</code></pre>
<p>jQuery&#x7684;&#x9009;&#x62E9;&#x5668;&#x5C31;&#x662F;&#x5E2E;&#x52A9;&#x6211;&#x4EEC;&#x5FEB;&#x901F;&#x5B9A;&#x4F4D;&#x5230;&#x4E00;&#x4E2A;&#x6216;&#x591A;&#x4E2A;DOM&#x8282;&#x70B9;&#x3002;</p>
<h3 id="&#x6309;id&#x67E5;&#x627E;">&#x6309;ID&#x67E5;&#x627E;</h3>
<p>&#x5982;&#x679C;&#x67D0;&#x4E2A;DOM&#x8282;&#x70B9;&#x6709;<code>id</code>&#x5C5E;&#x6027;&#xFF0C;&#x5229;&#x7528;jQuery&#x67E5;&#x627E;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-comment">// &#x67E5;&#x627E;&lt;div id=&quot;abc&quot;&gt;:</span>
<span class="hljs-keyword">var</span> div = $(<span class="hljs-string">&apos;#abc&apos;</span>);
</code></pre>
<p><em>&#x6CE8;&#x610F;</em>&#xFF0C;<code>#abc</code>&#x4EE5;<code>#</code>&#x5F00;&#x5934;&#x3002;&#x8FD4;&#x56DE;&#x7684;&#x5BF9;&#x8C61;&#x662F;jQuery&#x5BF9;&#x8C61;&#x3002;</p>
<p>&#x4EC0;&#x4E48;&#x662F;jQuery&#x5BF9;&#x8C61;&#xFF1F;jQuery&#x5BF9;&#x8C61;&#x7C7B;&#x4F3C;&#x6570;&#x7EC4;&#xFF0C;&#x5B83;&#x7684;&#x6BCF;&#x4E2A;&#x5143;&#x7D20;&#x90FD;&#x662F;&#x4E00;&#x4E2A;&#x5F15;&#x7528;&#x4E86;DOM&#x8282;&#x70B9;&#x7684;&#x5BF9;&#x8C61;&#x3002;</p>
<p>&#x4EE5;&#x4E0A;&#x9762;&#x7684;&#x67E5;&#x627E;&#x4E3A;&#x4F8B;&#xFF0C;&#x5982;&#x679C;<code>id</code>&#x4E3A;<code>abc</code>&#x7684;<code>&lt;div&gt;</code>&#x5B58;&#x5728;&#xFF0C;&#x8FD4;&#x56DE;&#x7684;jQuery&#x5BF9;&#x8C61;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code>[&lt;div id=&quot;abc&quot;&gt;...&lt;/div&gt;]
</code></pre><p>&#x5982;&#x679C;<code>id</code>&#x4E3A;<code>abc</code>&#x7684;<code>&lt;div&gt;</code>&#x4E0D;&#x5B58;&#x5728;&#xFF0C;&#x8FD4;&#x56DE;&#x7684;jQuery&#x5BF9;&#x8C61;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code>[]
</code></pre><p>&#x603B;&#x4E4B;jQuery&#x7684;&#x9009;&#x62E9;&#x5668;&#x4E0D;&#x4F1A;&#x8FD4;&#x56DE;<code>undefined</code>&#x6216;&#x8005;<code>null</code>&#xFF0C;&#x8FD9;&#x6837;&#x7684;&#x597D;&#x5904;&#x662F;&#x4F60;&#x4E0D;&#x5FC5;&#x5728;&#x4E0B;&#x4E00;&#x884C;&#x5224;&#x65AD;<code>if (div === undefined)</code>&#x3002;</p>
<p>jQuery&#x5BF9;&#x8C61;&#x548C;DOM&#x5BF9;&#x8C61;&#x4E4B;&#x95F4;&#x53EF;&#x4EE5;&#x4E92;&#x76F8;&#x8F6C;&#x5316;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> div = $(<span class="hljs-string">&apos;#abc&apos;</span>); <span class="hljs-comment">// jQuery&#x5BF9;&#x8C61;</span>
<span class="hljs-keyword">var</span> divDom = div.get(<span class="hljs-number">0</span>); <span class="hljs-comment">// &#x5047;&#x8BBE;&#x5B58;&#x5728;div&#xFF0C;&#x83B7;&#x53D6;&#x7B2C;1&#x4E2A;DOM&#x5143;&#x7D20;</span>
<span class="hljs-keyword">var</span> another = $(divDom); <span class="hljs-comment">// &#x91CD;&#x65B0;&#x628A;DOM&#x5305;&#x88C5;&#x4E3A;jQuery&#x5BF9;&#x8C61;</span>
</code></pre>
<p>&#x901A;&#x5E38;&#x60C5;&#x51B5;&#x4E0B;&#x4F60;&#x4E0D;&#x9700;&#x8981;&#x83B7;&#x53D6;DOM&#x5BF9;&#x8C61;&#xFF0C;&#x76F4;&#x63A5;&#x4F7F;&#x7528;jQuery&#x5BF9;&#x8C61;&#x66F4;&#x52A0;&#x65B9;&#x4FBF;&#x3002;&#x5982;&#x679C;&#x4F60;&#x62FF;&#x5230;&#x4E86;&#x4E00;&#x4E2A;DOM&#x5BF9;&#x8C61;&#xFF0C;&#x90A3;&#x53EF;&#x4EE5;&#x7B80;&#x5355;&#x5730;&#x8C03;&#x7528;<code>$(aDomObject)</code>&#x628A;&#x5B83;&#x53D8;&#x6210;jQuery&#x5BF9;&#x8C61;&#xFF0C;&#x8FD9;&#x6837;&#x5C31;&#x53EF;&#x4EE5;&#x65B9;&#x4FBF;&#x5730;&#x4F7F;&#x7528;jQuery&#x7684;API&#x4E86;&#x3002;</p>
<h3 id="&#x6309;tag&#x67E5;&#x627E;">&#x6309;tag&#x67E5;&#x627E;</h3>
<p>&#x6309;tag&#x67E5;&#x627E;&#x53EA;&#x9700;&#x8981;&#x5199;&#x4E0A;tag&#x540D;&#x79F0;&#x5C31;&#x53EF;&#x4EE5;&#x4E86;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> ps = $(<span class="hljs-string">&apos;p&apos;</span>); <span class="hljs-comment">// &#x8FD4;&#x56DE;&#x6240;&#x6709;&lt;p&gt;&#x8282;&#x70B9;</span>
ps.length; <span class="hljs-comment">// &#x6570;&#x4E00;&#x6570;&#x9875;&#x9762;&#x6709;&#x591A;&#x5C11;&#x4E2A;&lt;p&gt;&#x8282;&#x70B9;</span>
</code></pre>
<h3 id="&#x6309;class&#x67E5;&#x627E;">&#x6309;class&#x67E5;&#x627E;</h3>
<p>&#x6309;class&#x67E5;&#x627E;&#x6CE8;&#x610F;&#x5728;class&#x540D;&#x79F0;&#x524D;&#x52A0;&#x4E00;&#x4E2A;<code>.</code>&#xFF1A;</p>
<pre><code>var a = $(&apos;.red&apos;); // &#x6240;&#x6709;&#x8282;&#x70B9;&#x5305;&#x542B;`class=&quot;red&quot;`&#x90FD;&#x5C06;&#x8FD4;&#x56DE;
// &#x4F8B;&#x5982;:
// &lt;div class=&quot;red&quot;&gt;...&lt;/div&gt;
// &lt;p class=&quot;green red&quot;&gt;...&lt;/p&gt;
</code></pre><p>&#x901A;&#x5E38;&#x5F88;&#x591A;&#x8282;&#x70B9;&#x6709;&#x591A;&#x4E2A;class&#xFF0C;&#x6211;&#x4EEC;&#x53EF;&#x4EE5;&#x67E5;&#x627E;&#x540C;&#x65F6;&#x5305;&#x542B;<code>red</code>&#x548C;<code>green</code>&#x7684;&#x8282;&#x70B9;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> a = $(<span class="hljs-string">&apos;.red.green&apos;</span>); <span class="hljs-comment">// &#x6CE8;&#x610F;&#x6CA1;&#x6709;&#x7A7A;&#x683C;&#xFF01;</span>
<span class="hljs-comment">// &#x7B26;&#x5408;&#x6761;&#x4EF6;&#x7684;&#x8282;&#x70B9;&#xFF1A;</span>
<span class="hljs-comment">// &lt;div class=&quot;red green&quot;&gt;...&lt;/div&gt;</span>
<span class="hljs-comment">// &lt;div class=&quot;blue green red&quot;&gt;...&lt;/div&gt;</span>
</code></pre>
<h3 id="&#x6309;&#x5C5E;&#x6027;&#x67E5;&#x627E;">&#x6309;&#x5C5E;&#x6027;&#x67E5;&#x627E;</h3>
<p>&#x4E00;&#x4E2A;DOM&#x8282;&#x70B9;&#x9664;&#x4E86;<code>id</code>&#x548C;<code>class</code>&#x5916;&#x8FD8;&#x53EF;&#x4EE5;&#x6709;&#x5F88;&#x591A;&#x5C5E;&#x6027;&#xFF0C;&#x5F88;&#x591A;&#x65F6;&#x5019;&#x6309;&#x5C5E;&#x6027;&#x67E5;&#x627E;&#x4F1A;&#x975E;&#x5E38;&#x65B9;&#x4FBF;&#xFF0C;&#x6BD4;&#x5982;&#x5728;&#x4E00;&#x4E2A;&#x8868;&#x5355;&#x4E2D;&#x6309;&#x5C5E;&#x6027;&#x6765;&#x67E5;&#x627E;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> email = $(<span class="hljs-string">&apos;[name=email]&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&lt;??? name=&quot;email&quot;&gt;</span>
<span class="hljs-keyword">var</span> passwordInput = $(<span class="hljs-string">&apos;[type=password]&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&lt;??? type=&quot;password&quot;&gt;</span>
<span class="hljs-keyword">var</span> a = $(<span class="hljs-string">&apos;[items=&quot;A B&quot;]&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&lt;??? items=&quot;A B&quot;&gt;</span>
</code></pre>
<p>&#x5F53;&#x5C5E;&#x6027;&#x7684;&#x503C;&#x5305;&#x542B;&#x7A7A;&#x683C;&#x7B49;&#x7279;&#x6B8A;&#x5B57;&#x7B26;&#x65F6;&#xFF0C;&#x9700;&#x8981;&#x7528;&#x53CC;&#x5F15;&#x53F7;&#x62EC;&#x8D77;&#x6765;&#x3002;</p>
<p>&#x6309;&#x5C5E;&#x6027;&#x67E5;&#x627E;&#x8FD8;&#x53EF;&#x4EE5;&#x4F7F;&#x7528;&#x524D;&#x7F00;&#x67E5;&#x627E;&#x6216;&#x8005;&#x540E;&#x7F00;&#x67E5;&#x627E;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> icons = $(<span class="hljs-string">&apos;[name^=icon]&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&#x6240;&#x6709;name&#x5C5E;&#x6027;&#x503C;&#x4EE5;icon&#x5F00;&#x5934;&#x7684;DOM</span>
<span class="hljs-comment">// &#x4F8B;&#x5982;: name=&quot;icon-1&quot;, name=&quot;icon-2&quot;</span>
<span class="hljs-keyword">var</span> names = $(<span class="hljs-string">&apos;[name$=with]&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&#x6240;&#x6709;name&#x5C5E;&#x6027;&#x503C;&#x4EE5;with&#x7ED3;&#x5C3E;&#x7684;DOM</span>
<span class="hljs-comment">// &#x4F8B;&#x5982;: name=&quot;startswith&quot;, name=&quot;endswith&quot;</span>
<span class="hljs-comment">// $(&quot;[href!=&apos;#&apos;]&quot;) &#x9009;&#x53D6;&#x6240;&#x6709;&#x5E26;&#x6709; href &#x503C;&#x4E0D;&#x7B49;&#x4E8E; &quot;#&quot; &#x7684;&#x5143;&#x7D20;&#x3002;</span>
</code></pre>
<h3 id="&#x7EC4;&#x5408;&#x67E5;&#x627E;">&#x7EC4;&#x5408;&#x67E5;&#x627E;</h3>
<p>&#x7EC4;&#x5408;&#x67E5;&#x627E;&#x5C31;&#x662F;&#x628A;&#x4E0A;&#x8FF0;&#x7B80;&#x5355;&#x9009;&#x62E9;&#x5668;&#x7EC4;&#x5408;&#x8D77;&#x6765;&#x4F7F;&#x7528;&#x3002;&#x5982;&#x679C;&#x6211;&#x4EEC;&#x67E5;&#x627E;<code>$(&apos;[name=email]&apos;)</code>&#xFF0C;&#x5F88;&#x53EF;&#x80FD;&#x628A;&#x8868;&#x5355;&#x5916;&#x7684;<code>&lt;div name=&quot;email&quot;&gt;</code>&#x4E5F;&#x627E;&#x51FA;&#x6765;&#xFF0C;&#x4F46;&#x6211;&#x4EEC;&#x53EA;&#x5E0C;&#x671B;&#x67E5;&#x627E;<code>&lt;input&gt;</code>&#xFF0C;&#x5C31;&#x53EF;&#x4EE5;&#x8FD9;&#x4E48;&#x5199;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> emailInput = $(<span class="hljs-string">&apos;input[name=email]&apos;</span>); <span class="hljs-comment">// &#x4E0D;&#x4F1A;&#x627E;&#x51FA;&lt;div name=&quot;email&quot;&gt;</span>
</code></pre>
<p>&#x540C;&#x6837;&#x7684;&#xFF0C;&#x6839;&#x636E;tag&#x548C;class&#x6765;&#x7EC4;&#x5408;&#x67E5;&#x627E;&#x4E5F;&#x5F88;&#x5E38;&#x89C1;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> tr = $(<span class="hljs-string">&apos;tr.red&apos;</span>); <span class="hljs-comment">// &#x627E;&#x51FA;&lt;tr class=&quot;red ...&quot;&gt;...&lt;/tr&gt;</span>
</code></pre>
<h3 id="&#x591A;&#x9879;&#x9009;&#x62E9;&#x5668;">&#x591A;&#x9879;&#x9009;&#x62E9;&#x5668;</h3>
<p>&#x591A;&#x9879;&#x9009;&#x62E9;&#x5668;&#x5C31;&#x662F;&#x628A;&#x591A;&#x4E2A;&#x9009;&#x62E9;&#x5668;&#x7528;<code>,</code>&#x7EC4;&#x5408;&#x8D77;&#x6765;&#x4E00;&#x5757;&#x9009;&#xFF1A;</p>
<pre><code class="lang-javascript">$(<span class="hljs-string">&apos;p,div&apos;</span>); <span class="hljs-comment">// &#x628A;&lt;p&gt;&#x548C;&lt;div&gt;&#x90FD;&#x9009;&#x51FA;&#x6765;</span>
$(<span class="hljs-string">&apos;p.red,p.green&apos;</span>); <span class="hljs-comment">// &#x628A;&lt;p class=&quot;red&quot;&gt;&#x548C;&lt;p class=&quot;green&quot;&gt;&#x90FD;&#x9009;&#x51FA;&#x6765;</span>
</code></pre>
<p>&#x8981;&#x6CE8;&#x610F;&#x7684;&#x662F;&#xFF0C;&#x9009;&#x51FA;&#x6765;&#x7684;&#x5143;&#x7D20;&#x662F;&#x6309;&#x7167;&#x5B83;&#x4EEC;&#x5728;HTML&#x4E2D;&#x51FA;&#x73B0;&#x7684;&#x987A;&#x5E8F;&#x6392;&#x5217;&#x7684;&#xFF0C;&#x800C;&#x4E14;&#x4E0D;&#x4F1A;&#x6709;&#x91CD;&#x590D;&#x5143;&#x7D20;&#x3002;&#x4F8B;&#x5982;&#xFF0C;<code>&lt;p class=&quot;red green&quot;&gt;</code>&#x4E0D;&#x4F1A;&#x88AB;&#x4E0A;&#x9762;&#x7684;<code>$(&apos;p.red,p.green&apos;)</code>&#x9009;&#x62E9;&#x4E24;&#x6B21;&#x3002;</p>
<p>&#x5176;&#x4ED6;&#x5173;&#x4E8E; jquery &#x9009;&#x62E9;&#x5668;&#x8BE6;&#x60C5;<a href="https://www.jquery123.com/category/selectors/" target="_blank">&#x5B98;&#x7F51;</a></p>

                                
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